A robust speed control of brushless direct drive motor using integral variable structure control with sliding mode observer

A robust speed control technique for a brushless direct drive motor (BLDDM) using a variable structure approach is presented. The significant problems of the conventional variable structure approach is investigated in view of the practical implementation and an integral variable structure control (IVSC) combined with a sliding mode observer is proposed as an effective way of overcoming these problems. By employing the proposed scheme, complete robustness is achieved in the transient and steady state, and furthermore nearly continuous control is realized without chattering problems. The effectiveness of the proposed scheme is verified through comparative simulations and experiments for a BLDDM driven by a three phase voltage fed PWM inverter. All of the proposed algorithms are implemented using the software of the TMS320C30 DSP